Ki67 proliferation in core biopsies versus surgical samples - a model for neo-adjuvant breast cancer studies

Background: An increasing number of neo-adjuvant breast cancer studies are being conducted and a novel model for tumor biological studies, the "window-of-opportunity" model, has revealed several advantages. Change in tumor cell proliferation, estimated by Ki67-expression in pre-therapeutic core biopsies versus post-therapeutic surgical samples is often the primary end-point. The aim of the present study was to investigate potential differences in proliferation scores between core biopsies and surgical samples when patients have not received any intervening anti-cancer treatment. Also, a lack of consensus concerning Ki67 assessment may raise problems in the comparison of neo-adjuvant studies. Thus, the secondary aim was to present a novel model for Ki67 assessment. Methods: Fifty consecutive breast cancer cases with both a core biopsy and a surgical sample available, without intervening neo-adjuvant therapy, were collected and tumor proliferation (Ki67, MIB1 antibody) was assessed immunohistochemically. A theoretical model for the assessment of Ki67 was constructed based on sequential testing of the null hypothesis 20% Ki67-positive cells versus the two-sided alternative more or less than 20% positive cells.. Results: Assessment of Ki67 in 200 tumor cells showed an absolute average proliferation difference of 3.9% between core biopsies and surgical samples (p = 0.046, paired t-test) with the core biopsies being the more proliferative sample type. A corresponding analysis on the log-scale showed the average relative decrease from the biopsy to the surgical specimen to be 19% (p = 0.063, paired t-test on the log-scale). The difference was significant when using the more robust Wilcoxon matched-pairs signed-ranks test (p = 0.029). After dichotomization at 20%, 12 of the 50 sample pairs had discrepant proliferation status, 10 showed high Ki67 in the core biopsy compared to two in the surgical specimen (p = 0.039, McNemar's test). None of the corresponding results for 1000 tumor cells were significant - average absolute difference 2.2% and geometric mean of the ratios 0.85 (p = 0.19 and p = 0.18, respectively, paired t-tests, p = 0.057, Wilcoxon's test) and an equal number of discordant cases after dichotomization. Comparing proliferation values for the initial 200 versus the final 800 cancer cells showed significant absolute differences for both core biopsies and surgical samples 5.3% and 3.2%, respectively (p < 0.0001, paired t-test). Conclusions: A significant difference between core biopsy and surgical sample proliferation values was observed despite no intervening therapy. Future neo-adjuvant breast cancer studies may have to take this into consideration

strategy with NT-proBNP before echocardiography

Ruling out cardiac failure: Cost-benefit analysis of a sequential testing strategy with NT-proBNP before echocardiograph

Development of Competency Management System for Hydrometeorological Personnel Within The State Ltd. "Latvian Environment, Geology and meteorology Centre".

Maģistra darbā tika izstrādātas rekomendācijas VSIA “Latvijas Vides, ģeoloģijas un meteoroloģijas centrs” hidrometeoroloģiskā personāla kompetenču vadības sistēmas izveidei. Darba izstrādes laikā tika raksturota kompetenču nozīme organizāciju darbības nodrošināšanā, analizētas starptautiskās kompetenču prasības un rekomendācijas hidrometeoroloģiskajam personālam un to identifikācijas un novērtēšanas problemātika. Pētījuma gaitā tika konstatēts, ka dažādos hidrometeoroloģiskajos dienestos izmanto visai atšķirīgas pieejas kompetenču prasību ieviešanā. Arī pašu kompetenču identifikācija ir komplicēta un prasa dažādu instrumentu izmantošanu, jo nereti nav fiksējama tiešā veidā, bet gan izpaužas darbinieka kopējā snieguma ietvaros. Darba ietvaros tika izstrādāts praktisks, ilgtspējīgs risinājums starptautisko kompetenču prasību un rekomendāciju nodrošināšanai VSIA “Latvijas Vides, ģeoloģijas un meteoroloģijas centrs” – hidrometeoroloģiskā personāla kompetenču vadības sistēmas un tās IT arhitektūras uzbūve. Darbā sniegti priekšlikumi sekmīgai kompetenču vadības sistēmas ieviešanai, kā arī nepieciešamajiem atbalsta pasākumiem nacionālā līmenī. Darbs sastāv no trīs nodaļām un apakšnodaļām, tā kopējais apjoms ir 84 lpp. Darbā ietvertas 4 tabulas un 18 attēli, izmantoti 66 literatūras avoti.This master’s thesis work comprises recommendations for the development of competency management system for hydrometeorological personnel at the State Ltd. ‘Latvian Environment, Geology and Meteorology Centre’. The work presents characterization of the significant role and contribution competencies demonstrate within organizations, analysis of the international competency requirements and recommendations for hydrometeorological personnel as well as the complex and problematic nature of their identification and assessment. During the investigation, it was found that national hydrometeorological services use variable approaches while ensuring the fulfilment of competency requirements. Furthermore, competencies are often not detectable via direct observations, but rather demonstrated within the overall performance of the employee – therefore their identification requires the application of diverse tools of assessment. The results of this work present an applicable and sustainable solution aiding the fulfilment of international competency requirements and recommendations at the St.Ltd. ‘Latvian Environment, Geology and Meteorology Centre’ – the structure and IT architecture of the competency management system for hydrometeorological personnel. The work comprises proposals for successful implementation of the competency management system as well as the required national scale support actions. The thesis consists of three chapters and subchapters; its total volume is 84 pages. The work contains 4 tables and 18 figures, 66 references have been used

Ruling out cardiac failure : Cost-benefit analysis of a sequential testing strategy with NT-proBNP before echocardiography

Objectives. To estimate the possible economic benefit of a sequential testing strategy with NT-proBNP to reduce the number of echocardiographies. Methods. Retrospective study in a third-party payer perspective. The costs were calculated from three Swedish counties: Blekinge, Östergötland, and Uppland. Two cut-off levels of NT-proBNP were used: 400 and 300 pg/mL. The cost-effectiveness of the testing strategy was estimated through the short-term cost avoidance and reduction in demand for echocardiographies. Results. The estimated costs for NT-proBNP tests and echocardiographies per county were reduced by 33%–36% with the 400 pg/mL cut-off and by 28%–29% with the 300 pg/mL cut-off. This corresponded to a yearly cost reduction of approximately €2–5 million per million inhabitants in these counties. Conclusion. The use of NT-proBNP as a screening test could substantially reduce the number of echocardiographies in the diagnostic work-up of patients with suspected cardiac failure, as well as the associated costs

Proliferation of the breast epithelium in relation to menstrual cycle phase, hormonal use, and reproductive factors

The proliferative rate in normal breast epithelium from 58 women undergoing reduction mammoplastics was studied using the formalin resistant antibody Ki-S5, and related to age at operation, menstrual cycle phase, family history of breast cancer, height and weight, parity, and hormonal use. The breast tissue from women operated on in the luteal menstrual cycle phase (day 15-28 among oral contraceptive (OC) users) had significantly higher proliferative rate than breast tissue removed from women in the follicular phase (day 1-14) (p = 0.01). Among women presently exposed to hormones, those with a positive family history of breast cancer among first and second degree relatives had significantly higher values than cases without such history (p = 0.02). Weight was not significantly related to proliferation rate, while a short height was associated with a significantly higher proliferation rate (p = 0.04). Women who used OCs before the first full-term pregnancy (FFTP) had a significantly higher proliferation rate compared with never users or late users (p = 0.04). No significant difference was seen between parous versus nulliparous women. The results from the univariate analysis persisted in multivariate models. An especially high proliferation rate was seen in young women with both a positive family history and present hormonal use (p = 0.001). Overall, it was found that young women had a non-significantly higher proliferation rate than older women (p = 0.10). Due to small sample size, these results must be regarded as preliminary, especially in the subgroup analyses

Reverse lectin ELISA for detecting fucosylated forms of alpha 1-acid glycoprotein associated with hepatocellular carcinoma

Altered fucosylation of glycoproteins is associated with development of hepatocellular carcinoma (HCC). Lectins have been commonly used to assay changes in fucosylation of plasma glycoproteins. In the present study a recombinantly engineered form of the fucose binding lectin Aleuria aurantia (AAL) consisting of a single binding site for fucose (S2), was used to construct a reverse lectin ELISA method. Microtiter plates coated with the S2 lectin were used to capture glycoproteins from plasma samples followed by antibody detection of S2-bound fucosylated alpha 1-acid glycoprotein (S2-bound AGP). The method was used to compare the level of S2-bound AGP in serum samples from a small cohort of patients with hepatitis, cirrhosis or HCC. Using the reverse S2 lectin ELISA it was shown that the levels of S2-bound AGP was significantly higher in HCC patients compared to non-cancer patients and that there was also a significant elevation of S2-bound AGP in HCC patients compared to cirrhosis patients. There was no correlation between the level of S2-bound AGP and total AGP concentration. The performance of S2-bound AGP in differentiating HCC from cirrhosis samples or hepatitis samples were compared to other markers. A combination of S2-bound AGP, alpha-fetoprotein and AGP concentration showed performances giving area under receiver operating curves of 0.87 and 0.95 respectively.Funding Agencies|Stockholm County Council [20140329, 20150403]; Swedish Society of Medicine, Gastroenterology Fund [SLS 505601]; Ruth and Richard Julins Foundation [40661, 45300]; Uppsala Bio, Bio-X; Health Research Council of Southeast of Sweden [FORSS-389021]</p

AIB1 is a new putative prognostic biomarker in the luminal A and B-like (HER2-negative) classification of invasive lobular carcinoma

Body: Background: Estrogen receptor (ER) positive HER2-negative breast cancer comprises 75–80% of all breast cancer. Thisfraction is even higher (>90%) in invasive lobular carcinoma (ILC). According to the St Gallen surrogate definitions of the intrinsicsubtypes, Ki67 and progesterone receptor (PgR) are used to classify these tumors as luminal A- and luminal B-like(HER2-negative). These guidelines are based on information derived from patient materials with mixed histological types, wherethe vast majority of the patients have invasive ductal carcinoma. The `luminal-like classification´ together with histological grade,tumor size and lymph node status is widely used in the clinic for prognostication. The aim of the present study was to investigateif the same markers are applicable for ILC, and furthermore, if additional biomarkers involved in the endocrine signaling system,e.g. Amplified in breast cancer 1 (AIB1) and the putative G protein-coupled estrogen receptor (GPER), might providecomplementary prognostic information.Patients: Two hundred and thirty-three (N = 233) well-characterized patients with primary ILC, diagnosed between 1980 and1991 were included. Forty-two percent of the patients received adjuvant endocrine treatment and 2 % received adjuvantchemotherapy. All biomarkers were analyzed immunohistochemically on tissue microarray, whereas histological grade wasevaluated on whole sections according to Elston and Ellis (NHG). The primary endpoint was breast cancer mortality (BCM).Results: In univariable analyses with 10-year follow-up, Ki67 (high vs. low), NHG (3 vs. 1+2) and AIB1 (high vs. low) weresignificantly associated to BCM (Hazard Ratio: 4.7, 95% CI: 2.1–10.4, p 95% CI: 1.4–7.2, p = 0.005 respectively), whereas PgR (respectively). Essentially the same effect was seen after multivariable adjustment for lymph node status (+ vs. -), tumor size (>20mm vs. according to St Gallen surrogate definitions did not show significant prognostic differences between the two groups (p = 0.12).Patients with AIB1) had a 10-year BCM of 4.2% (95% CI: 1.4–12%). This group constituted 34% of the patients included in the present study.Conclusions: In contrast to other previous studies, where breast cancers of mixed histological types were included, PgR was notsignificantly associated to prognosis in the ER-positive HER2-negative subgroup in the present study, consisting only of ILC. Theprognostic role of PgR and the clinical usefulness of the luminal A and B-like (HER2-negative) classification (using only Ki67 andPgR) in ILC is still to be further investigated. The prognostic importance of Ki67 and NHG in this subgroup was, however,confirmed also in ILC, and AIB1 might be a new putative prognostic factor. By combining Ki67, NHG, and AIB1, together withlymph node status and tumor size, a group of patients with an excellent prognosis could be identified

Quartz Crystal Microbalance Platform for SARS-CoV-2 Immuno-Diagnostics

Rapid and accurate serological analysis of SARS-CoV-2 antibodies is important for assessing immune protection from vaccination or infection of individuals and for projecting virus spread within a population. The quartz crystal microbalance (QCM) is a label-free flow-based sensor platform that offers an opportunity to detect the binding of a fluid-phase ligand to an immobilized target molecule in real time. A QCM-based assay was developed for the detection of SARS-CoV-2 antibody binding and evaluated for assay reproducibility. The assay was cross-compared to the Roche electrochemiluminescence assay (ECLIA) Elecsys (R) Anti-SARS-CoV-2 serology test kit and YHLO's chemiluminescence immunoassay (CLIA). The day-to-day reproducibility of the assay had a correlation of r(2) = 0.99, p &lt; 0.001. The assay linearity was r(2) = 0.96, p &lt; 0.001, for dilution in both serum and buffer. In the cross-comparison analysis of 119 human serum samples, 59 were positive in the Roche, 52 in the YHLO, and 48 in the QCM immunoassay. Despite differences in the detection method and antigen used for antibody capture, there was good coherence between the assays, 80-100% for positive and 96-100% for negative test results. In summation, the QCM-based SARS-CoV-2 IgG immunoassay showed high reproducibility and linearity, along with good coherence with the ELISA-based assays. Still, factors including antibody titer and antigen-binding affinity may differentially affect the various assays' responses